| abstract |
The present invention relates to the chiral intermediate (S, S)-2 of moxifloxacin, the asymmetric synthesis method of 8-diazabicyclo [4,3,0] nonane (I), first 3-pyrrolidone compound ( Formula III or formula IV) undergoes dehydration reaction with chiral amine, and the dehydrated product is reduced under different reducing conditions to obtain an enantiopure compound of formula (II), and the compound of formula (II) undergoes intramolecular ring closure and removal of chiral auxiliary The compound of formula (I) is obtained. The present invention also relates to a 3-pyrrolidone of formula (III) or formula (IV) and a preparation method thereof, , wherein, R is an amino protecting group; * in formula (II) is the chiral center mark of a chiral prosthetic group; R 1 and R 2 are independently C 1-4 alkyl, C 1- substituted by hydroxyl or carboxyl 4 alkyl, aryl, carboxyl, C 1-4 alkoxycarbonyl or carbamoyl; when Z=H 2 , Y is chlorine, bromine, iodine or hydroxysulfonate; when Z=O, Y is hydrogen , hydroxyl or C 1-4 alkoxy; R 3 of formula (III) is hydrogen or C 1-4 alkyl; Y of formula (IV) is chlorine, bromine, iodine or hydroxysulfonate. |